Heater exhaust system



Aug. 31, 1948. L'A. WILLIAMS, JR 2,443,132

mum mwsw sy s'rsu Filed June 27, 1946 advantageously mama Aug. s1, 194sUNITED STA ES i PATENT OFFICE I mm A- J to Stewart-Warner Indianapolis,Ind" "in" Chicago, m.

a corporation of Virginia Application June 27, ms, Serial No. 679303 2Claims. (Cl. 231-123) 1 v The present invention relates to heaterexhaust systems. More particularly it is concerned with an improvedexhaust system for use with a combustion heater of a type suitable forheating the occupied space of an automobile or the like.

One of the objects of the present invention is to-provide a novelexhaust system for use-with gasoline or other liquid fuel burning heaterwhich conducts the heater exhaust to the atmosphere at a point outsidethe occupied space and also provides against possibility of unburnedliquid fuel fiowing from theend of the exhaust pipe in the event theheater-fails to start.

Another object of the present invention is to provide a combustionheater installation for an automobile or the like and an'exhaust systemfor the heater such that the exhaust from the heater is discharged tothe atmosphere at any point outside the vehicle without the exhaustsystem constituting a possible fire hazard.

Still another object of the present invention is to provide an improvedexhaust system for accomplishing the above at low cost.

Other objects and advantages will become apparent from the followingdescription of a preferred embodiment of my invention which is aillustrated in the accompanying drawings.

2 present invention and therefore needs no detailed description.Essentially. it comprises a burner. not shown, which is-supplied'withgasoline by way of a fuel line 8. leading from the inlet con-' nectionof the engine carburetor 32, the carburetor receiving fuel. through aline 34 from: the fuel tank, this line leading" to an engine-driven fuelpumptl and from the pump to a settling bowl 88 and thence by way of afuel line 40 to. the carburetor.

Within the heater il fuel received fronrthe line 30 is' burnedin thepresence of air and the hot products of combustion thus producedzpassthrough a heat exchanger within the heater C38? In the drawings. inwhich similar characters of reference refer to similar parts throughoutthe several views:

Fig.- 1 is a vertical sectional view through automobile enginecompartment and the adiacent portion of the driver's compartment showingthe automobile engine. the heating system, and other adjacent equipment;

Fig. 2 is a fractional sectional view of a portion of the heater exhaustsystem; while Pig. 3 is a sectional view of a fitting that may be usedin conjunction with the exhaust system of ,the present invention.

In- Fig. 1 of the drawings I have shown a portion of an automobilehaving an engine compartment II and a passenger-occupied portion If.These two portions are separated by a dash I. A combustion type heaterII is located within the engine compartment at any convenient point andis supplied at one end with ventilating air by a blower II which isconnected on its inlet side by way of a duct II to an inlet opening 22disposed behind the engine radiator grill 24 or atsome other convenientlocation. Hot air is piped from the heater by a duct II to one or moredistributing openings II located within the. driver's compertinent.-

ing and thence to an exhaust fitting 42. An exhaust pipe 44 is connectedto this fitting and leads to. the atmosphere at a point II such thatproducts of combustion cannot fi'nd access to the occupied portion ofthe vehicle. In Fig. '1, this exhaust point is shown as being locatedbeneath the fioor boards ll of the vehicle. A heater of this generaltype is described and illustrated in greater detail in' the copendingapplication .of William A. Marshall, .Jr., Serial No. 615,040, filedSeptember 7, 1945, for Heating apparatus. An other heater of suitabletype will be found in the copending application of George W. Allen andVernon N. Trarnontini, filed June 14. 1948,-'}! or Heaters, and whichhas been given Serial No. 678,778.

In such heaters, combustion is usually started by a hot wire igniterwhich may'possibly fail in operation or for some other reason the heatermay fail to start even though fuel has been turned on and is beingsupplied to the'combustion chamher at the usual rate. Under theseconditions. a portion of the fuel may be vaporized so that it passesfrom the end of the exhaust pipe 44 in the form of gasoline and airmixture. Thismixture.

however. is not combustible since it is too lean to burn. The gasespassing from the exhaust pipe are therefore not dangerous and do notconstitute a fire hazard.-

Inasmuch as a portion of the liquid gasoline is not vaporized within theheater this fuel would normally drain down the inside of the exhaustpipe and drip from the end thereohand under some conditions mightconstitute a fire hazard. In order to avoid this possible fire hazard Ihave provided an arrangement for removing all liquid gasoline from theexhaust pipe at an intermediate point and for disposing of this liquidportion ina safe manner.

The mechanism for accomplishing this includes a drawn or otherwisesuitably formed sheet metal through the pipe 64 dricallydianged end 52thereof forms a elm fit in place therein. portion of this ring forms aradially inwardly projecting annulus l4 and a second cylindrical flangeI formed at the smaller that the flange flange I! is located upstream ofthe flange ll. thereby providing an annular pocket 00 between the flange50 and the inner surface of the exhaust pipe which forms a trap to catchany liquid gasoline flowing along the side wall of the exhaust pipe.Gases flowing through the pipe pass through the opening in the center ofthe ring I! and continue on to the remotely located outlet.

In order to remove collected liquid fuel from the pocket I, a fitting 00is secured to the exhaust pipe at a point opposite the trap and apassage 82 extends from the fitting I through the side wall of theexhaust pipe such that the-inner end of this passage opens within thepocket I closely adjacent the upstream edge of the annular ring 84. Asmall diameter tube I4 is connected to a fitting 00 at one end,its'opposite end being connected to a fitting it threaded into theintake manifold 68 of the automobile engin Because of the low pressureprevailing within the intake manifold 60 there will be a continuous fiowthrough the pipe M from the inlet end of the passage 62 to the manifold6|. The rate of flow of air or gases through this passage is so slight,however, that it will have no disturbing influence upon the operation ofthe automobile. On the other hand, if gasoline in liquid form shouldflow down ,the side wall of the pipe ll it will be caught in the annularpocket 50 and will be carried along the stream of gases flowing so thatit passes into the intake manifold and thence to the engine cylinderswhere it is harmlessly consumed.

Although I have shown the ring '0 within the exhaust pipe 44 as formingthe trap for the purpose of catching liquid gasoline and transferringthis liqu d to the tube 54 leading to the intake manifold, it will beappreciated that a liquid trap of any other suitable type may be used,the specific ring shown being merely illustrative of one convenientforming such a trap.

The fitting It in Fig. 3 is shown as including a portion 10 which formsa venturi shaped passage 82 through which the gases fiow on their way tothe intake manifold. This fitting. although not necessary in manyinstallations, is none the less an advantage in that it tends tomaintain the rate of fiow through the tube 04 substantially constantregardless of the degree of vacuum within the intake manifold 68. Thisis probably and inexpensiveexpedient for 4 because a slight pressurereduction within the manifold I is suiilcient to cause'gases to flowthrough the venturi at or approaching the speed been reached an! themanifold 80 will not cause a substantial increase in the rate of flowthrough the Venturi throat. 1 From the above description of a preferredembodiment of my invention it will be seen-that I have provided a simpleand efilcient arrangement for preventing liquid gasoline from flowingout of the heater exhaust pipe to a place where it might produce a flrehazard. It will be appreciated also that this liquid gasoline has safelybeen removed to the intake manifold of the engine without the necessityfor dumping any appreei able quantiy of exhaust manifold. Thus. a heaterused with the present system may have much greater heat outputcapacities than is possible if all of the heater exhaust is carried tothe engine manifold.

Having described my invention, what I claim as new and useful and desireto secure by letters Patent of the United States is:

1. A heating system for an automotive vehicle having an internalcombustion engine including an intake manifold comprising: a liquid fuelbuming heater, means for supplying liquid fuel to said heater forcombustion therein, an exhaust pipe connected to said heater forremoving products of combustion therefrom, said exhaust. pipe emptyingto the atmosphere, means forming aliquid trap in said exhaust pipe,conduit means connected between said trap and the intake manifold, andrestricting means in said conduit for limiting the rate of flowtherethrough to a small proportion of the rate of flow of exhaust gasesthrough said exhaust pipe.

2. A heating system for an automotive vehicle having an internalcombustion engine including an intake manifold comprising: a liquid fuelburnfor supplying liquid fuel to said connected to said heater forremoving products of combustion therefrom, said exhaust pipe emptying tothe atmosphere, means forming a liquid trap in said exhaust pipe,conduit means connected between said trap and the intake manifold, andvmeans forming a fiow restricting venturi inside said conduit.

, LYNN AIWIILIAMB. Jn.

REFERENCES crrnn The following references are of record in the file ofthis patent:

UNITED STATES PATENTS 00 Number Name Date 2,213,656 Pinkerton et alSept. 3, 1940 2,226,612 McCollum Dec. 31, 1940 2,400,509 Heymann May 21,1946 gasesorairintothe' heater for combustion therein, an exhaust pipe

